The invention relates to therapies for human papilloma virus infections.
Infection with human papilloma virus (HPV) is common. HPV can be transmitted sexually, and it is estimated that 20-80% of sexually active adults have been infected. While a majority of infections are asymptomatic, infection can lead to the development of genital warts (which have a prevalence of about 1-5% among adults) and cancer of the anogenital tract. Another type of cancer, cervical cancer, is strongly associated with HPV (Frazer, Genitourin. Med. 72:398-403, 1996). HPV types 6, 11, 16, 18, 31, and 33 are often associated with an increased risk of cancer, with types 16 and/or 18 being detected in more than 90% of cervical carcinomas (van Driel et al., Ann. Med. 28:471-477, 1996). Types 6 and 11 are also associated with anogenital warts. For reviews of papilloma viruses and their associated pathologies, see Shah et al., xe2x80x9cChapter 66: Papillomaviruses,xe2x80x9d In: Virology, 3rd Edition, Fields et al., Eds., Raven Press, Philadelphia, pp 2077-2109, 1996, and zur Hausen, J. Natl. Cancer Inst. 92:690-698, 2000.
There is currently no safe and effective way to treat or prevent warts or the diseases described above by targeting the immune system. Efforts to develop such therapies have been hampered for several reasons, one of which is the dogma that antigens from a single HPV type elicit a limited, type-specific immune response. Consequently, it has been suggested that a cocktail containing antigens from several different HPV types is necessary for a broadly effective HPV therapy (Caine et al., Science 288:1753, 2000).
The present invention is based, in part, on the discovery that a fusion protein containing a protein from one HPV type can be used to treat a disease or condition that is caused by infection with another HPV type. For example, an HPV type 16 antigen, fused to a bacterial heat shock protein (hsp), was effective in treating human anogenital warts caused by HPV types other than type 16 (e.g., HPV types 6 and 11). This result supports two contentions: (1) that warts can be treated with an HPV protein and (2) that therapeutic agents aimed at HPV need not contain protein antigens from different HPV types in order to be broadly effective.
Accordingly, the invention features a method of treating a wart in a subject by administering to the subject a composition containing (1) an hsp, or an immunostimulatory fragment thereof, and (2) an HPV protein (e.g., an antigenic protein such as the E7 protein of, e.g., HPV type 16) or an antigenic fragment thereof. These components may be referred to herein as xe2x80x9ccomponent (1)xe2x80x9d and xe2x80x9ccomponent (2),xe2x80x9d respectively. The hsp (or the immunostimulatory fragment thereof) and the HPV protein (or the antigenic fragment thereof) can be either simply combined in the same preparation or more closely associated by chemical conjugation or fusion (i.e., one can administer a fusion protein having the components described herein or a nucleic acid molecule that encodes it). When combined, conjugated, or fused, component (1) and component (2) would be administered simultaneously. Each component can, however, also be administered separately (e.g., sequentially), and component (2) can be administered without component (1). The method described above can include a step in which a subject who has, or who is suspected of having, a wart is identified (in the context of treating the subject, identification would be made before administration of the therapeutic agent begins). Physicians and others of ordinary skill in the art are well able to identify such subjects.
The methods of the invention can also be used to prevent a wart, in which case a subject who desires, or who would benefit from, wart prevention (rather than a subject who already has a wart) is identified.
The invention also features methods of treating a subject who has a disease or condition caused by an infection with an HPV of a first type (e.g, type 5, 6, 11, 18, 31, 33, 35, 45, 54, 60, or 70) by administering to the subject a composition containing (1) an hsp, or an immunostimulatory fragment thereof, and (2) a protein of an HPV of a second type (e.g., type 16) or an antigenic fragment thereof. That is, the HPV of the xe2x80x9cfirst typexe2x80x9d and the HPV of the xe2x80x9csecond typexe2x80x9d are different from one another; they are of two different HPV types. The hsp (or the immunostimulatory fragment thereof) and the HPV protein (or the antigenic fragment thereof) can be either simply combined in the same preparation or more intimately associated by chemical conjugation or fusion (i.e., one can administer a fusion protein having the components described herein or a nucleic acid molecule that encodes it). When combined, conjugated, or fused, component (1) and component (2) would be administered simultaneously. Each component can, however, also be administered separately (e.g., sequentially), and component (2) can be administered without component (1). Here again, the method can include a step in which a subject who has, or is suspected of having, an HPV infection (or a disease or condition associated therewith) is identified.
When a subject who is infected with a first HPV type is given a composition that includes an HPV of a second type, the method can be carried out before an HPV infection is typed, before it is manifest, or before it has occurred (i.e., one need not know the particular HPV type a subject has been infected with, or will be infected with, before treatment or prophylaxis can begin). When the methods are preventative, they can include a step in which a subject who desires, or who would benefit from, prevention of an HPV infection is identified.
The compositions described herein can be administered in amounts that are sufficient to treat the wart (by, for example, reducing the size or altering the shape of the wart, or by ameliorating a symptom associated with a wart (e.g., the pain often associated with a plantar wart); when a subject has more than one wart, treatment can encompass reducing the number of warts). Similarly, the compositions described herein can be administered in amounts that are sufficient to treat the disease (e.g., cancer (such as cervical cancer or anal cancer) or other condition (e.g., dysplasia (such as cervical or anal dysplasia)) that is caused by, or associated with, an HPV infection. Although warts are mentioned separately above, warts also constitute a condition caused by or associated with HPV. Physicians and others of ordinary skill in the art will recognize an effective xe2x80x9ctreatmentxe2x80x9d of a wart or an HPV-associated disease or condition when there is a diminution in an undesirable physiological affect associated with the wart or the disease or condition. The clinical and physiological manifestations of a wart, as well as those of a disease or condition associated with HPV infection, are discussed in, for example, Fauci et al., Harrison""s Principles of Internal Medicine, 14th Edition, McGraw-Hill Press, New York, pp 302-303 and 1098-1100, 1998.
xe2x80x9cSubjectsxe2x80x9d who can benefit from the methods described herein are those who can be infected by papilloma viruses (e.g., mammals such as humans, livestock (e.g., cows, horses, pigs, sheep, and goats), and domestic animals (e.g. cats and dogs)). The wart can be one that occurs on the subject""s genitalia, skin, or internal organs (such as the warts that appear on the vocal cords in recurrent respiratory papillomatosis (RRP; also known as juvenile laryngeal papillomatosis (JLP) or adult-onset RRP)).
The invention further includes the use of one or more of the compositions described herein (including those that contain proteins, protein conjugates or fusion proteins, or the nucleic acid molecules that encode them) for the treatment of subject who has warts or a disease or conditions associated with (or caused by) an HPV infection, in accordance with the methods described herein. The invention further includes the use of one or more of such compositions in the manufacture of a medicament for the treatment of subject who has warts or a disease or conditions associated with (or caused by) an HPV infection, in accordance with the methods described herein.
An xe2x80x9cantigenic fragmentxe2x80x9d of a protein (e.g. an HPV protein) is any portion of the protein that, when administered in accordance with the methods described herein, elicits, in a subject, an immune response that is either a fragment-specific or specific for the protein from which the fragment was obtained. The immune response can be either a humoral or a cell-mediated response. For example, an antigenic fragment can be an HLA class I peptide antigen, such as described below. One of ordinary skill in the art will recognize that the immune response desired in the context of the present invention can be generated not only by intact proteins and fragments thereof, but also by mutant proteins (e.g., those that contain one or more additions, substitutions (e.g. conservative amino acid substitutions) or deletions in their amino acid sequence). Mutant HPV antigens can be readily made and tested for their ability to work in the context of the present invention.
An xe2x80x9cimmunostimulatory fragmentxe2x80x9d of a protein (e.g., an hsp) is any portion of the protein that, when administered in accordance with the methods described herein, facilitates an immune response by an antigen. For example, if the immune response to an HPV protein is facilitated when that HPV protein is administered with (e.g., fused to) a fragment of an hsp, that fragment is an immunostimulatory fragment of an hsp. One of ordinary skill in the art will recognize that the immune response can also be facilitated by mutant hsps (e.g., hsps that contain one or more additions, substitutions (e.g., conservative amino acid substitutions) or deletions in the amino acid sequence). Mutant hsps can be readily made and tested for their ability to facilitate an immune response to an HPV antigen.
The methods of the invention provide an efficient means of: (1) treating or preventing warts and (2) treating or preventing a disease or condition caused by (or associated with) an infection with one HPV type with (i.e., using) a composition containing an HPV of another type. Consequently, a composition containing an HPV antigen of a single HPV type can be used in many, if not most, subjects, regardless of the HPV type with which they are infected (or with which they may become infected). It is surprising that HPV compositions are effective in these circumstances (i.e., circumstances requiring cross-reactivity). It has been thought that HPV antigens of one type cannot elicit an effective immune response against another type. Other features or advantages of the present invention will be apparent from the following detailed description, and also from the claims.